Need help

I am trying to get data to work on on floodplains of California. I have tried all the available sites like California department of Hydrology, FEMA, State of Cali Geopotral and all. All they do is direct me to online map, but what I need is downloadable data that I can play in arcmap. I can see the attribute table and all the map information there in online map but once I open the map in arcmap in my PC there is no attribute table and data seen except the map layer. Where can I get the data that I can import in arcmap to work on? Thanks In advance.